Process for packing and aging meat products

ABSTRACT

The invention relates to a method for packaging meat products by feeding a flat plastic foil to a filling tube and thereby shaping it into a cylindrical shape that surrounds the filling tube and is sealed at the overlapping edges, whereby the meat product is filled into the foil tube via the filling tube and the tube is then sealed at the ends and detached. It is thereby essential that the flat foil for use with raw meat products is extruded from long-fibered synthetic fibers and has a water and/or steam permeability of at least 40 g/m 2 d and that the packed raw meat products are subsequently preserved by the removal of moisture and/or by smoking.

The invention relates to a method for packaging meat products, inparticular sausage products, by feeding a flat plastic foil to a fillingtube and thereby shaping it into a cylindrical form that surrounds thefilling tube and is heat-sealed at the overlapping edges, whereby themeat product is filled into the flexible foil tube thus formed via thefilling tube and the flexible tube is then sealed at the ends anddetached.

The said method is extensively used for sausage packaging, but also forpackaging cheese, herb butter and the like. An essential advantage isthat the flat foil, which can be pulled off from rolls, is shaped intocalibers of different sizes and automatically heat-sealed at theoverlapping edges and simultaneously filled with the product. After thedesired amount of product has been filled in, the flexible tube issealed by two closely successive clips or the like and separated betweenthe clips, so that the sausages are already dispensed from the packagingand filling machine in a separated form.

in this case, mono or composite foils are used which are impermeable tosteam and oxygen, whereby it is important that the foil is easilyheat-sealable, so that the overlapping edges can be quickly and reliablyjoined by the addition of heat.

However, the described method is to date only used for aged meatproducts such as boiling sausage, cooking sausage and other foods suchas herb butter, soft cheese, etc., i.e. for those food products that donot require any aging after packaging, but should be tightly sealedvis-à-vis the surroundings and, if necessary, also boiled.

On the other hand, in all other meat products which are to be aged orpreserved by drying, i.e. e.g. raw sausages, semipreserved products andthe like—salami sausages are best known—it is necessary to make thecasings either from natural skins or non-edible cellulose fibre skinsand collagen skins, optionally reinforced with cellulose, because onlycasings of this type which are permeable to steam enable the drying ofthe packaged product. However, casings of this type are considerablymore awkward in handling. Thus, with natural skins, there is the problemthat they cannot be produced and processed cost-effectively and,moreover, are only available in specific calibers. If casings ofcollagens and optionally cellulose are used instead, then a pretreatmentwith acids, lyes and water is required for the coagulation,neutralization and washing out.

The manufacturing of said casings represents a further expensiveprocess: The casings must be gathered after they have been produced,i.e. mechanically pushed together to form a caterpillar, so that theycan be transported in a space-saving manner to the filling machine. Thisrequires that the casings be moistened prior to the gathering, so thatthey become soft and flexible and are not damaged by the gatheringwheels of the gathering machine during the mechanical load. After thegathering process, the gathered, moist casings must again be dried tothe desired residual moisture to prevent the formation of mold.

The processor or filler must then again moisten these caterpillars bysoaking in water before the filling process, so that the casings can befed to the filling machine. This soaking also conceals a high hygienicrisk.

However, if the gathered casing is delivered to the filling machine in amoistened state, i.e. ready to be filled, then a chemical must be addedto the water which is required for the moistening to prevent theformation of mold. Moreover, the damp caterpillar must be transported tothe filling machine in a container which is impermeable to steam toprevent drying.

Based on this, the object of the present invention is to improve theknown packaging method for meat products in such a way that raw meatproducts, which must still undergo a drying and aging process afterpackaging, can be packed while avoiding the aforementioned problems.

According to the invention, this object is solved in that the flat foilfor use with raw meat products, in particular for raw sausage andsemipreserved products, consists of a fleece which is made with acomponent of at least 80% long-fibered synthetic fibers and has a waterand/or steam permeability of at least 40 g/m²d and that the packed rawmeat products are subsequently preserved by the removal of moistureand/or by smoking.

The natural skins and collagen and fiber casings thusfar required forraw sausage products can be replaced by a fleece foil of this type. Themanufacture and production of the casings is thereby considerablysimplified. In particular, the moistening which is no longer requiredprior to the gathering of the casings and also prior to filling isomitted. Moreover, the hygienic conditions when using the foil accordingto the invention are significantly more advantageous.

To obtain the desired drying and aging in the shortest time possible, itis recommended that the foil have a water and steam permeability of morethan 100 g/m²d, preferably more than 150 g/m²d.

In addition, the foil should also be permeable to gas, so that gasesthat occur during the aging process can escape.

In order that these properties can be optimally realized, it isrecommended that the synthetic fibers be extruded with a fiber length ofat least 5 mm, preferably at least 50 mm. It is most advantageous towork with an endless fiber. The fiber(s) is/are placed crisscrossadjacent to and on top of one another and then heat-sealed together atthe points of contact or intersection. As a result, the desiredpermeability and the required stability can be guaranteed.

The thickness of the foils is selected in such a way that a foil weightof at least 30 g/m², at the most 300 g/m², sets in. The preferred rangeis between 40 g/m² and 200 g/m².

Especially suitable as material for the fibers are polyvinylidenechloride, polyamide, polypropylene, polyester and/or polyethylene fromwhich a heat-sealable fleece foil is produced in the spun/bond method.It is also within the scope of the invention to work with fibers made ofother materials, as long as the fibers have a casing of a heat-sealableor sealable plastic, in particular, therefore, of a thermoplasticmaterial.

In addition, it is essential and unusual for packaging raw meat productsthat the fleece foil be supplied to the filling tube without priormoistening. This also applies when they are brought onto the fillingtube in a gathered form prior to folding over.

Generally, the filled raw meat products must still then age for a longtime. Therefore, in a further development of the invention, it isrecommended that the flat foil be treated with preservatives, inparticular potassium sorbate, prior to the filling process. As a result,the danger of mold formation, which is considerably higher in raw meatproducts than in conventionally filled products, is clearly reduced.

Moreover, it can be advantageous to treat the flat foil with propyleneglycol and/or glycerine, so that it becomes softer and more easilypeelable.

The aforementioned treatments can advantageously be carried out in sucha manner that potassium sorbate and/or propylene glycol and/or glycerineis dissolved in water and the foil passed through an immersion bathformed therewith. Any residues of the solution still adhering to thesurface are then removed by rolling, stripping or the like.Advantageously, the aforementioned immersion bath contains about 10 to30% propylene glycol, about 5 to 20% glycerine and about 1 to 10%potassium sorbate.

To facilitate removal of the foil from the product, it can berecommended, depending on the type of product, that the foil have ananti-adhesive coating on the side facing the product. The thickness ofthis anti-adhesive coating is in the μ-range. Preferably, it consists ofcellulose, acrylate and other substances known to a person skilled inthe art, whereby liquid smoke or other flavouring substances are alsosuitable, if one wishes to simultaneously influence the taste of theproduct. Other coatings for the foil are also possible, perhaps tocontrol its permeability.

The flat foil is advantageously made completely of long-fiberedsynthetic fibers; however, it is also within the scope of the inventionto add about 15% to about 20% foreign fibers, in particular cellulosefibers or derivatives thereof.

It is decisive for the use according to the invention of the knownpackaging method for raw meat products that the products can bepreserved after packaging by removal of moisture and/or smoking, i.e.that the foil has adequate water and/or steam permeability. Thispermeability is reduced in the overlapping area of the foil edges, thatis there where the edges are heat-sealed together to form a flexibletube. It is therefore recommended that this area be stippled after thebonding or heat-sealing, i.e. to make numerous microholes, so that thegas and moisture permeability is just as good as in the non-heat-sealedfoil area.

Further particulars of the invention can be found in the followingdescription of an embodiment and the drawings, showing

FIG. 1 a schematic illustration of the filling system;

FIG. 2 the individual procedural steps.

First, a roll with the flat foil 1 according to the invention can beseen in FIG. 1. This is a fiber fleece which is made from an endlessfiber. The fiber is coextruded from a PET (polyethylene terephthalate)core and a PET (polyethylene) casing and has a diameter of 5μ to about100μ, preferably about 10 to about 50μ. It is laid out on an underpad inan orderly or disorderly fashion in strands which are adjacent to andabove one another, so that an area weight of about 20 g/m² to about 200g/m² results. This fleece is then heat-sealed at certain points, so thata so-called spun/bond material is produced. It is cut into the desiredwidth (about 3 m) and length (about 2000 m) and wound on supply rolls.From there, the foil is separated in such a width that it results in thedesired caliber of the sausage with a peripheral overlapping of a fewmillimeters when being shaped into the form of a flexible tube, so thatthe overlapping width for the joining of the two foil edges in aheat-sealing station is sufficient.

After the flat foil has been produced, it is also advantageously treatedby preservatives, so that it is better suitable for the later use withfor raw meat products. This treatment is advantageously carried out witha solution of bactericidal and/or fungicidal preservatives. Thesesubstances are applied to the foil by spraying or an immersion bath.Subsequently, they are optionally scraped off the surface of the foil,however, they remain inside the foil and consequently have a longerlasting effect than with preserving by heat or drying. Suitablepreservatives are sorbates, benzoates, sulfites, nitrides, acetates,propionates and other legally certified substances for food. An aqueoussolution with sorbic acid or sorbates, optionally with additionalsubstances, is especially suitable for the present application.

The foil 1 treated in this way is pulled off a supply roll via avertically freely movable dancer roll 2 and conveyed to a shapingshoulder 3. By means of this shaping shoulder, the foil is shapedcylindrically in a known manner, whereby it is placed about a fillingtube 7. The foil 1 thus made into a flexible tube 1 a is then run alonga heat-sealing beam 4 which heats the overlapping foil edges and sealsthem. The sealing surface can be perforated with microholes to improveits permeability. The tubular sealed casing is conveyed by conveyorbelts 5 into a gathering area 8 which is in the vicinity of the outletend of the filling tube 7. A clipping machine 6, where the foil tube isclipped off and detached, adjoins it.

FIG. 2 illustrates the procedural steps in detail:

The tube end sealed by a clip 1 b and the gathering area 8 found on thefilling tube 7 can be seen in Fig. a. After the tube end has beenclipped, the filling process starts, as a result of which the sealedtube end is pressed forward into the position shown in Fig. b. After thepreset portion has been dispensed, the dosing feeder actuates thebinding process. For this purpose, according to Fig. c, the tube is tiedoff with fingers 1 c in a known manner and, according to Fig. d, a braid1 d is pulled. Two clips are placed on the pulled braid at a distancefrom the clipping machine 6. A blade 9 between the clips then separatesthe filled sausage. It is transported away by a conveyor belt or via adischarge tray. The process is repeated at the sealed tube end on theright side.

Of course, it is also within the scope of the invention to provide thefleece foil according to the invention as a prefabricated tube which isheat-sealed on the overlapping longitudinal edges and to then conveythis tube to the filling tube 7.

In summary, the invention offers the advantage that raw meat products,in particular raw sausage and semipreserved products such as salami, cannow be quickly and hygienically packaged with any caliber desired andcan age in the packaging. Moreover, the fleece foil according to theinvention can be processed by rolls of up to 2000 m length, whereas theprevious skins were limited to 60-80 m length.

1. A method for packaging meat products, in particular sausage products,by feeding a flat plastic foil to a filling tube and thereby shaping itinto a cylindrical form that surrounds the filling tube and is sealed atthe overlapping edges, whereby the meat product is filled into the foiltube (1 a) thus formed via the filling tube (7) and the tube (1 a) isthen sealed at the ends and detached, characterized in that the flatfoil (1) for use with raw meat products, in particular for raw sausageand semipreserved products, consists of a fleece which is made with acomponent of at least 80% long-fibered synthetic fibers and a waterand/or steam permeability of at least 40 g/m²d and that the packed rawmeat products are subsequently preserved by the removal of moistureand/or by smoking.
 2. The method according to claim 1, characterized inthat the water and steam permeability is at least 150 g/m²d.
 3. Themethod according to claim 1, characterized in that the synthetic fibershave a length of at least 50 mm, preferably at least 100 mm up toendless fibers.
 4. The method according to claim 2, characterized inthat the weight of the flat foil is at least 20 g/m², at most 300 g/m²,preferably between 40 g/m² and 200 g/m².
 5. The method according toclaim 1, characterized in that the synthetic fibers consist ofpolyamide, polypropylene, polyester and/or polyethylene.
 6. The methodaccording to claim 1, characterized in that the synthetic fibers have acasing of heat or high-frequency sealable material, in particularthermoplastic materials.
 7. The method according to claim 6,characterized in that the casing has a lower melting point than thecasing material.
 8. The method according to claim 1, characterized inthat the synthetic fibers are deposited adjacent to and on top of oneanother and are joined together in the spun/bond process to form a flatfleece foil.
 9. The method according to claim 1, characterized in thatthe flat foil (1) is delivered to the filling tube (7) withoutmoistening.
 10. The method according to claim 1, characterized in thatthe flat foil (1) is treated with preservatives.
 11. The methodaccording to claim 1, characterized in that the flat foil (1) is treatedwith a solution of propylene glycol and/or glycerine.
 12. The methodaccording to claim 11, characterized in that, in addition, the solutioncontains potassium sorbate.
 13. The method according to claim 11,characterized in that the solution contains about 10 to 30% propyleneglycol, about 5 to 20% glycerine and optionally about 1 to 10% potassiumsorbate.
 14. The method according to claim 1, characterized in that theflat foil (1) has a coating, in particular an anti-adhesive coating, onits side facing the meat product.
 15. The method according to claim 14,characterized in that the thickness of the anti-adhesive coating is inthe μ-range.
 16. The method according to claim 14, characterized in thatthe anti-adhesive coating consists of cellulose, acrylate and/or liquidsmoke.
 17. The method according to claim 1, characterized in that theflat foil (1) has a maximum of about 15% to about 20% foreign fibers, inparticular of cellulose.
 18. The method according to claim 1,characterized in that microholes are arranged on the overlapping, sealededges to increase the gas and moisture permeability.
 19. Use of the flatfoil in the automatic packaging of foods, in particular according to themethod of claim 1, characterized in that the flat foil used for raw meatproducts, in particular for raw sausage and semipreserved products,consists of a fleece which is made with a component of at least 80%long-fibered synthetic fibers and a water and/or steam permeability ofat least 40 g/m²d and that the packed raw meat products are subsequentlypreserved by the removal of moisture and/or by smoking.
 20. Useaccording to claim 19, characterized in that the foil is provided as aprefabricated tube which is heat-sealed on the overlapping longitudinaledges.